Microtome

ABSTRACT

The microtome has a sample carrier movable along a first linear guide and a hand drive movable along a substantially linear path of motion that is substantially perpendicular to the direction of motion of the sample carrier. A deflecting device is provided to deflect the motion of the hand drive into a motion in the direction of the linear guide of the sample carrier. By deflection of the paths of motion between the hand drive and the sample holder, the motion of the hand drive can take place substantially horizontally forward and backward and convert the motion of the hand drive into a motion of the sample carrier which is substantially perpendicular to the motion of the hand drive. The cutting motion takes place in a substantially vertical direction, so that the sections can be removed or washed away from the inclined back surface of the cutting knife or knife carrier.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a microtome for the production of histologicalsections, particularly of plant and animal tissues, which are intendedfor microscopic inspection.

2. Discussion of Prior Art

So-called slide microtomes are known from the Soviet Inventor'sCertificate SU-783626 or from the Applicant's EP-A1 0 416 354, and havea baseplate with an object carrier and in addition substantiallyhorizontal guides. A knife holder is movably received in the horizontalguides and is provided with a handle. The knife holder moves back andforth, linearly and horizontally, and its motion is coupled with a feeddrive of the sample carrier.

Slide microtomes are distinguished by their simple construction and theconsequent low price. Moreover they are distinguished, as long as theuser follows a sufficient routine, by operation which is not tedious. Onthe other hand, it is a disadvantage that the removal of the microtomesections is quite complicated. This disadvantage clearly becomesmanifest in the latest slide microtomes, which have an electrical driveof the sample feed, such as that offered by the Applicant under thedesignation “OHM 440”. Indeed, because of the electrical sample feed,the knife holder no longer needs to be moved over the whole length ofthe guideway in order to cause the sample feed. Instead, it issufficient to move the knife or the knife holder over a path lengthwhich roughly corresponds to the thickness of the sample along thedirection of cutting, since the electronics of the sample feed detectsthe reversal of motion of the knife holder. Thus with small samples, asubstantially higher cutting frequency is possible. However, it has beenfound that the time required for removal of sections limits the cuttingfrequency.

Moreover, so-called rotary microtomes are known, which are described,for example, in DE-P 33 01 921 or in DE-C1 35 39 138. Such a rotarymicrotome usually has a baseplate on which a slide with a cutting knife,movable parallel to the baseplate, is received. The slide with thesample carrier is received in a further guide, which is directedsubstantially perpendicular to the baseplate and consequently permits amotion of the sample carrier perpendicular to the baseplate. The driveof the cutting motion, which runs perpendicular to the baseplate, of thesample carrier takes place by means of a hand crank in the form of adisc with a horizontal axis of rotation.

As regards removal of sections, such rotary microtomes are considerablymore user-friendly than slide microtomes, since the sections which areproduced are produced in the forward region of the microtome, lie on theback face, inclined forward and downward, of the microtome knife orknife holder, and can be floated off there, for example by the use of awater bath. However, such rotary microtomes have the disadvantage thatthe rotary motion of the handle is quite tiring. The number of sectionsproduced during the course of a working day is thus lower for rotarymicrotomes than for slide microtomes.

It would be conceivable to provide a motor to drive the cutting motion,in order to eliminate this disadvantage. However, the motors which wouldbe required for this would nearly double the price of the microtome.

SUMMARY OF THE INVENTION

The invention therefore has as its object to provide a microtome with ahand drive for the cutting motion, which microtome is not very tiring tooperate, and at the same time enables the sections which are produced tobe easily removed.

This object is attained by a microtome having a first linear guide, asample carrier movable in a guide direction along the first linearguide, a hand drive movable along a substantially linear path of motionsubstantially perpendicular to the guide direction of the first linearguide and a deflecting device for deflecting motion of the hand driveinto motion in the guide direction of the first linear guide.

The microtome according to the invention has a sample carrier which ismovable along a first linear guide. Moreover, the microtome has a handdrive which is movable along a substantially linear path of motion,wherein the path of motion of the hand drive is substantiallyperpendicular to the direction of motion of the sample carrier.Furthermore, means are provided to deflect the motion of the hand driveinto a motion in the direction of the linear guide of the samplecarrier.

By the deflection of the paths of motion between the hand drive and thesample holder, the motion of the hand drive can take place substantiallyhorizontally forward and backward of the microtome (push and pull motionby the operator), which is considered to be particularly favorable fromthe ergonomic viewpoint, and can be converted into a motion of thesample carrier, substantially perpendicular to the motion of the handdrive. The cutting motion can thus take place in a substantiallyvertical direction, so that the sections which are produced can beremoved or washed away from the inclined back surface of the cuttingknife or knife carrier.

The result of the invention is a microtome which unites the respectivespecific advantages of both the slide microtome and the rotarymicrotome, without having the specific disadvantages of each of thesetypes of construction.

The means for deflection of the motion can be constructed, in a simpleembodiment example, as a belt drive which is guided over severaldeflecting rollers. Of course, a belt drive makes possible only aninteger transmission ratio between the motion of the hand drive and thatof the sample carrier. A counterweight is to be provided, for weightequalization, on the driving belt of the belt drive, having a mass whichcorresponds to the transmission ratio and to the mass of the samplecarrier including its guide slide, chosen such that the two massesequalize each other in each position of the sample carrier.

Alternatively to this, the means for deflection of the direction ofmotion can be constructed as a plate in the form of a circular segment,or as a lever arm. According to the ratio of the two arm lengths of thelever arm, or according to the ratio of the distances of the deflectionpoints from the mounting point of the circular segment shaped plate,different, and even non-integral, transmission ratios can be set in thisembodiment between the motion of the hand drive and that of the samplecarrier. The use of a hydraulic system for the deflection of the motionslikewise makes possible optional, even non-integral, transmissionratios.

In an advantageous embodiment example of the invention, a device isprovided for the detection of a reversal of motion of the samplecarrier. By the detection of the reversal of motion, control of theforward feed of the sample can take place independently of the pathlengths of the cutting motion. The path length of the sample carrier canbe chosen by the user himself, corresponding to the thickness of thesample which is about to be cut, and does not need to pass, in order torelease the feeding of the return stroke, along a minimum path which isdetermined by the construction.

The detection of the reversal of motion is particularly advantageous inconnection with a motor drive for the sample feed, and with anelectronic control circuit which controls the motor in the case that areversal of motion is detected.

In a further advantageous embodiment example, a hand drive is provided,or a hand drive can be installed, on two mutually opposite sides of themicrotome. The ergonomic advantages of the microtome according to theinvention can thus be fully realized for both left-handed andright-handed persons.

Furthermore, in the microtome according to the invention, the knifecarrier of the microtome is to be movable, for the sample feed, alonglinear guideways perpendicular to the cutting motion of the sampleholder. The masses to be accelerated during the cutting motion can thusbe kept to a minimum, since the mechanism for the sample feed does notcount as part of the masses to be accelerated. The invention aredescribed in further detail hereinbelow with reference to the embodimentexamples shown in the accompanying Figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Perferred embodiments of the present invention will now be described,taken together with the drawings, in which:

FIG. 1 is an elementary sketch of a first embodiment example of theinvention with a plate in the form of a circular segment as means fordeflection of the motion;

FIG. 2 is an elementary sketch of a simplified form of the embodimentaccording to FIG. 1;

FIG. 3a shows, in section, a microtome with a belt drive and a 1:1transmission ratio between the motion of the hand drive and the motionof the sample carrier;

FIG. 3b shows a front view of the microtome in FIG. 3a;

FIG. 3c shows a sectional view of a microtome with a belt drive for a2:1 transmission ratio between the motion of the hand drive and themotion of the sample carrier;

FIG. 4 shows a sectional view of a microtome with a hydraulictransmission of the motion of the hand drive to the motion of the samplecarrier; and

FIG. 5 shows a block circuit diagram relating to the control of thesample feed and return stroke.

DETAILED DESCRIPTION OF THE PERFERRED EMBODIMENTS

The embodiment according to FIG. 1 contains a baseplate (1), on whichthe knife carrier (2) is received in the forward region, facing theuser, and is movable back and forth horizontally, that is, in thedirection of the baseplate (1). The sample carrier (3), with a sample(4), is received, vertically movable, on a guide (5) which is orientedperpendicularly to the baseplate (1). The guided slide of the samplecarrier (3) has a groove (6) in which there engages a pin (7) of a plate(8) of circular segment shape. The circular segment plate (8) is mountedfor rotation about a rotation axis (9). The plate (8) has a second pin(10), spaced apart from the first pin (7), and engaging in the groove(11) of a horizontally guided slide (12). A horizontal guideway (13) isconnected to the baseplate (1) of the microtome in order to guide theslide (12). A handle (14) for the manual operation of the cutting motionis provided on the slide (12).

The circular segment plate (8) with the two pins (7) and (10) forms aunit for the transmission and deflection of the horizontal motion of thehandle (14) into the substantially vertical direction of motion of thesample carrier (3). The slide (12), the guide (13), and the handle (14)form a hand drive device.

For the operation of the microtome of FIG. 1, the user displaces theslide (12) along the horizontal guides (13) towards himself, by means ofthe handle (14). Upon this motion of the slide (12), the pin (10)engaging in the groove (11) rotates the plate (8) counter-clockwise, andwith it the attached pin (7) which engages in the groove (6) of thesample carrier (3). The sample carrier (3) is thereby moved in thedirection towards the cutting knife of the microtome. As a result ofthis motion, the cutting of a section of the sample (4) takes place.Upon the subsequent motion of the handle (14) rearward away from theuser, the sample carrier (3) is again lifted up and the feed drive (notshown in the drawing) of the knife carrier (3) executes a horizontalmotion rearward through a predetermined path length, in the directiontowards the sample carrier (3). Upon the subsequent motion of the handle(14) forward again, the cutting of a further section from the sampletakes place.

The embodiment according to FIG. 2 is a simplified form of theembodiment according to FIG. 1. The constructional elements denoted by 1through 9 correspond to those of FIG. 1, and are therefore not furtherdescribed here. Differing from the embodiment according to FIG. 1, thehandle (14) is received directly at the place on the circular segmentplate (8) at which the pin (10) is provided in the mode of embodimentaccording to FIG. 1. In this embodiment, the circular segment (8) andits axis of rotation (9) simultaneously serve as parts of the hand drivedevice and of the device for the transmission and deflection of themotion from the handle to the sample carrier (3). In this embodiment,the path of motion of the handle (14) is not exactly linear, but is asection, running substantially horizontally, of a circular path. Thisdeviation can hardly be detected by the operator, however, since thehandle (14) is distanced sufficiently far from the rotation axis (9) ofthe circular segment (8) and consequently the radius of the circularpath is greater by at least a factor of 2 than the path length along thecircular path.

Instead of a plate (8) of circular segment shape, the deflection of thedirection of motion from the hand drive (14) to the sample holder (3)can also be realized by a pivotably mounted lever arm. Such a lever armis derived in a simple manner from the circular segment shaped plate (8)if this is cut along the lines (15), shown dashed in FIG. 2, parallel tothe connection axes between the handle (14) and the rotation axis, andbetween the pin (7) and the rotation axis (9).

The increase or reduction transmission ratio of the motions of thesample carrier and of the hand drive can be optionally realizedaccording to the ratio of the two effective lever lengths.

In the embodiment example according to FIG. 3a, the baseplate of themicrotome is denoted by (20). The guideways (21), extending along thebaseplate (20), are provided in the baseplate (20) for the feed motionof the knife carrier (22). The cutting knife (23) is received on theknife carrier (22). A stepping motor (26) is provided for driving thefeed motion, and has a threaded spindle (25) which runs parallel to theguideways (21) and which is screwed into a corresponding internal threadin the knife carrier (22).

A portal frame (27) which stands substantially perpendicularly of thebaseplate (20) and which has guideways (28) is fixedly arranged on thebaseplate (20). The sample carrier (30) with the sample (31) to be cutis received in the forward region of the sample carrier slide (29).

On the side remote from the sample carrier (30) is a driving belt (36),for example, a wide steel band or a V-belt, which is guided by a totalof four deflection rollers (32-35), and which is screwed to the samplecarrier slide (29). Two deflecting rollers (32, 34) of the fourdeflecting rollers (32-35) insure that the driving belt (36) is guidedin the forward region parallel to the guideways (28) in the portal frame(27). The other two deflecting rollers (33, 35) serve to insure that thedriving belt (36) in the region of the handle (40) is guidedperpendicularly of the guideways (28) in the portal frame (27). Thuswhen the handle (40) moves horizontally in the direction of the doublearrow (Pfl), a vertical motion results of the sample carrier slide (29)in the direction of the double arrow (Pf2).

The four deflecting rollers (32-35) also insure that the cutting motiontakes place when the handle (40) is pulled towards the user. Moreover,it is insured that the handle (40) is arranged in the lower part of themicrotome, in the neighborhood of the baseplate (20). Both of thesefeatures are particularly favorable from the ergonomic viewpoint.

The use of four deflecting rollers furthermore insures that the drivingbelt (36) runs about vertically between two further deflecting rollers(32, 33), the direction of motion of the belt (36) in this region beingthe reverse of the direction of motion at the sample carrier slide (29).A balance weight (48) is provided on the driving belt (36) between thesetwo deflecting rollers (32, 33); its mass corresponds to that of thesample carrier slide (29) with the sample carrier (30). Due to thisweight equalization, the sample carrier slide remains stationary at anyposition of the guideway (28) where it is placed, so that only therequired accelerating forces, but no additional weight forces, have tobe applied at any place when the motion is reversed by means of thehandle (40).

The drive pin (37) of a slide potentiometer (38) is also provided on theside of the sample carrier slide (29) remote from the sample carrier(30). When the sample carrier slide (29) moves, the resistance of thepotentiometer (38) changes correspondingly. The voltage drop at thepotentiometer (38), or more precisely the change of this voltage drop,serves for the detection of the reversal of motion of the sample carrierslide (29) and for the corresponding control of the motor (26) for thefeed motion. The required evaluation electronics (not shown) is providedon a board (39) within the microtome, and the individual steps whichtake place in it are described in detail hereinbelow with reference toFIG. 5.

FIG. 3b shows the front view of the microtome of FIG. 3a. As is known, arespective handle (40) is provided on each of two opposite sides of themicrotome, to drive the cutting motion of the sample carrier slide (29).The microtome thus has the same ergonomic advantages for right-handedand left-handed people. It is of course also possible to provide,instead of two handles (40), only a single handle (40) which can beselectively fitted by the user to one of the two opposite sides of themicrotome.

In the microtome of FIGS. 3a and 3 b, the transmission ratio between themotion of the hand drive (40) and the sample carrier slide (29) is 1:1.In this case, the driving belt (36) is constructed as a circulatingendless belt. In contrast to this, the sample carrier slide (41) itself,in the embodiment example according to FIG. 3c, has two rotatabledeflecting rollers (42, 43), over which the driving belt (44) istrained. The driving belt is constructed as a belt having two ends inthis embodiment example and runs with its ends parallel to the guidewaysof the sample carrier slide (41), and is fastened at its ends, by meansof spacers (45, 46) to the portal frame (27), which has the guidewaysfor the sample carrier slide (41) of the microtome. In this embodiment,the motion of the hand drive (47) is stepped down in a ratio of 2:1 tothe motion of the sample carrier slide (41); this means that therequired stroke of the hand drive (47) is twice as large as the strokeof the sample carrier slide (41). The mass of the balance weight (48)needs only to amount to half the mass of the sample carrier slide (41)with the sample holder (30) received on it, giving an overall reductionof the masses to be accelerated.

Moreover, the forces required for the acceleration of the sample carrierslide (41) are only half as large, due to the 2:1 reduction ratio, asthose in the case of a 1:1 transmission ratio, so that the totalaccelerating forces which have to be applied amount to less than half ofthose in the embodiment example according to FIG. 3a. The detection ofthe reversal of motion of the sample carrier slide (41) and thecorresponding drive of the motor for the advance of the microtome knifetakes place in the same manner as in the embodiment example according toFIG. 3a, and is therefore not described again here.

In the embodiment example according to FIG. 4, a hand-operated hydraulicsystem is provided for driving the cutting motion of the sample carrierslide (50). For this purpose, the hand drive knob (54) is connected by arod (55) to a displacement piston (57) in a first hydraulic cylinder(56). This hydraulic cylinder (56) is connected by means of twohydraulic ducts (58, 59) to a second hydraulic cylinder (52), thedisplacement piston (53) of which is rigidly connected via a rod (51) tothe sample carrier slide (50). When the drive knob (54) is moved towardsthe front side of the microtome, the displacement piston (57) pushes thehydraulic oil in the first cylinder (56) through the duct (58) into thesecond hydraulic cylinder (52) and pushes its displacement pistonupwards, so that the sample carrier slide (50) is likewise movedupwards. Simultaneously, the displacement piston (53) pushes the excesshydraulic oil in the upper chamber of the second hydraulic cylinder (52)via the second duct (59) into the rear chamber of the first hydrauliccylinder (56). When the handle (54) is moved in the reverse direction,the corresponding reverse functional sequence takes place, so that thesample carrier slide (50) is guided downwards for the cut. The cutcorrespondingly takes place, in the embodiment example according to FIG.4, during is pushing motion of the hand drive (54), in contrast to thepulling motion in the embodiment examples according to FIGS. 3a and 3 c.If it is desired that, in the case of a hydraulic force transmission tothe sample carrier slide, the cutting motion is effected downwardsduring a pulling motion, that is, a motion of the handle (54) forwards,it is only necessary to interchange the connections of the two ducts (58and 59) to the second hydraulic cylinder (52). For weight equalization,a counterweight (61) is also provided in this embodiment example, and isattached to the sample carrier slide (50) by means of a cord which istrained over a roller (60).

In this embodiment example also, a reversal of the motion of the samplecarrier slide (50) is detected by means of a slide potentiometer (38),and when a reversal is detected, the stepping motor (26) is controlledfor driving the feed motion of the microtome knife.

In the embodiment examples which have been described, the sections whichare produced lie on the back face (24), which is inclined downwards andforwards, of the knife carrier, in the front region of the microtome, sothat the sections can be easily and conveniently removed or floated off,as in rotary microtomes.

FIG. 5 shows details of the functional steps which take place in acontrol processor of the electronics board (39) for the detection of thereversal of motion of the sample carrier slide. In a first step (70),the value of the position transducer, that is, the resistance of theslide potentiometer (38) set at that moment, is read out and temporarilystored. In a subsequent step (71), the instantaneous resistance iscompared with the stored resistance of the previous measurement; thiscan take place, for example, by the formation of a difference orquotient of the actual value with the previous value. In a subsequentstep (72), it is decided from the comparison value whether a cuttingmotion (sample carrier slide is moved downwards) or a return motion(sample carrier slide is moved upwards) is taking place. It iscorrespondingly decided whether the knife carrier is to next execute afeed motion or a return motion. In the case that a cutting motion isascertained, it is decided in a subsequent function step (73), by acomparison of the direction of motion during the previous measurement,whether the direction of motion has reversed. If this question isanswered in the negative, the position transducer is read afresh, andthe routine is run through anew. If on the other hand a reversal of thedirection of motion was detected in function step (73), the motor (26)is subsequently controlled such that the knife carrier (22) is moved inthe direction towards the portal frame (27) over a path length whichcorresponds to the sum of a return stroke distance and a predeterminedsection thickness. After this, the routine returns to the first functionstep (70), so that the position transducer is read out anew and theroutine is run through anew.

In the case that a return motion was detected in the function step (72),it is ascertained in the subsequent function step (75), by a comparisonwith the direction value of the previous measurement, whether a reversalof direction has taken place. If this question is answered in thenegative, the routine returns to the function step (70), the positiontransducer is read out anew, and the routine is run through anew. If onthe other hand a reversal of the direction of motion is detected in thefunction step (75), which means that a change from a cutting motion tothe return motion had taken place between the present measurement andthe previous measurement, the stepping motor (26) is then controlled ina subsequent function step (76) such that the knife carrier (22) ismoved away from the portal frame (37) of the microtome through thepredetermined return stroke. The routine then returns again to thefunction step (70), the position transducer is read out anew and theroutine is run through anew.

In order to insure that a feed motion or return motion is not startedevery time there is a small shaking of the hand drive (40), it is alsorespectively tested in the function steps (73 and 75) whether at leastone predetermined safe path, which has a value between 2 mm and 5 mm,was carried out in the same direction. Otherwise, it is decided by theroutine in function steps (73 and 75) that no reversal of motion hastaken place.

Detection of the reversal of motion for the release of the feed or ofthe return insures that this release also reliably takes place when theuser limits the length of the cutting motion and the return motion tothe minimum which is predetermined by the object to be cut. Inparticular, with small samples, the user can execute very short motions,based on the detection of the reversal of motion together with thelinear motion of the hand drive (40), so that long idle paths of thecutting and return motion are avoided. A high cutting frequency can thusbe obtained, particularly with small samples.

In the examples shown in FIGS. 3a-3 c and 4, the guides of the samplecarrier slide and the hand drive are exactly perpendicular to eachother. Such an arrangement is provided for equipment which is to beplaced on a horizontal support. However, it is also possible toconstruct the microtome to be placed on an inclined surface, as forexample in cryostatic microtomes, the motion of the sample carrier slidebeing inclined at an angle of up to 30° to the vertical. In suchembodiment examples, the deflection angle between the motion of thesample carrier slide and that of the hand drive are to be chosen suchthat the motion of the hand drive takes place in the horizontaldirection in this case also.

We claim:
 1. A microtome, comprising: a first linear guide (5, 28), asample carrier slide (3, 29, 41, 50) moveable in a guide direction alongsaid first linear guide (5, 28), a hand drive, said hand drive includinga hand drive handle (14, 40, 47, 54) moveable along a substantiallylinear path of motion substantially perpendicular to said guidedirection of said first linear guide (5, 28), said substantially linearpath of motion of said hand drive handle (14, 40, 47, 54) having a fixeddirection, and a deflecting device (8, 36, 44) for deflecting motion ofsaid hand drive handle (14, 40, 47, 54) into motion in said guidedirection of said first linear guide (5, 28).
 2. The microtome accordingto claim 1, further comprising a detection device (37, 38, 39) fordetecting motion reversal of said sample carrier (3, 30).
 3. Themicrotome according to claim 2, further comprising a motor (26) to feedsamples, and an electronic control circuit (39) for controlling saidmotor upon detecting said motion reversal of said sample carrier (3,30).
 4. The microtome according to claim 1, wherein said hand drive (40)and a second hand drive are arranged at two opposite sides of saidmicrotome.
 5. The microtome according to claim 1, wherein saiddeflecting device (8) comprises a plate having a circular segment shape.6. The microtome according to claim 1, wherein said deflecting device(36) comprises a belt drive guided by a plurality of deflecting rollers(32-35, 42, 43).
 7. The microtome according to claim 6, wherein saidsample carrier includes a guiding slide (29, 41) and said belt driveincludes a driving belt (36, 44) said sample carrier including saidguiding slide having a mass, further comprising a balance weight (48) onsaid driving belt (36, 44) at a position where said balance weight (48)moves relative to said guiding slide (29, 41) with a reduction ratio,said balance weight (48) having a mass corresponding to the mathematicalproduct of the mass of said sample carrier (30) including said guidingslide (29, 41) and said reduction ratio.
 8. The microtome according toclaim 2, wherein said deflecting device comprises a hydraulic system(51, 53, 55, 57).
 9. The microtome according to claim 3, furthercomprising a knife carrier (2, 22) movable along a linear guideway (21)perpendicularly to said guide direction of said sample carrier slide (3,29, 41, 50) for feeding a sample.
 10. The microtome according to claim7, wherein said path of motion of said hand drive (14, 40 47, 54) ishorizontally oriented.
 11. A microtome, comprising: a first linear guide(5, 28), a sample carrier slide (3,29, 41, 50) moveable in a guidedirection along said first linear guide (5, 28), a hand drive, said handdrive including a hand drive handle (14, 40, 47, 54) moveable along asubstantially linear path of motion substantially perpendicular to saidguide direction of said first linear guide (5, 28), said substantiallylinear path of motion of said hand drive handle (14, 40, 47, 54) havinga fixed direction, a deflecting device (8, 36, 44) for deflecting motionof said hand drive handle (14, 40, 47, 54) into motion in said guidedirection of said first linear guide (5, 28), and a knife carrier in afront region of said microtome, said knife carrier having a back facedownwardly and forwardly inclined.
 12. The microtome according to claim2, in which said deflecting device comprises a lever arm.
 13. Amicrotome according to claim 11, further comprising a detection device(37, 38, 39) for detecting motion reversal of said sample carrier (3,30).
 14. The microtome according to claim 11, further comprising a motor(26) to feed samples, and an electronic circuit (39) for controllingsaid motor upon detecting said motion reversal of said sample carrier(3, 30).
 15. The microtome according to claim 11, wherein said handdrive (40) and a second hand drive are arranged at two opposite sides ofsaid microtome.
 16. The microtome according to claim 11, wherein saiddeflecting device (8) comprises a plate having a circular segment shape.17. The microtome according to claim 11, wherein said deflecting devicecomprises a lever arm.
 18. The microtome according to claim 11, whereinsaid deflecting device (36) comprises a belt drive guided by a pluralityof deflecting rollers (32-35, 42, 43).
 19. The microtome according toclaim 18, wherein said sample carrier includes a guiding slide (29, 41)and said belt drive includes a driving belt (36, 44), said samplecarrier including said guiding slide (29, 41) having a mass, furthercomprising a balance weight (48) on said driving belt (36, 44) at aposition, where said balance weight (48) moves relative to said guidingslide (29, 41) with a reduction ratio, said balance weight (48) having amass corresponding to the mathematical product of the mass of saidsample carrier including said guiding slide and said reduction ratio.20. The microtome according to claim 11, wherein said deflecting devicecomprises a hydraulic system (51, 53, 55, 57).
 21. The microtomeaccording to claim 11, further comprising a knife carrier (2, 22)moveable along a linear guideway (21) perpendicularly to said guidedirection of said carrier slide (3, 29, 41, 50) for feeding a sample.22. The microtome according to claim 11, wherein said path of motion ofsaid hand drive (14, 40, 47, 54) is horizontally oriented.
 23. Amicrotome, comprising: a first linear guide (5, 28), a sample carrierslide (3, 29, 41, 50) moveable in a guide direction along said firstlinear guide (5, 28), a hand drive, said hand drive including a handdrive handle (14, 40, 47, 54) moveable along a substantially linear pathof motion substantially perpendicular to said guide direction of saidfirst linear guide (5, 28), said substantially linear path of motion ofsaid hand drive handle (14, 40, 47, 54) having a fixed direction, and alever arm connecting said hand drive and said sample carrier anddeflecting a motion of said hand drive handle into a motion in saidguide direction of said first linear guide.
 24. A microtome, comprising:a first linear guide (5, 28), a sample carrier slide (3, 29, 41, 50)moveable in a guide direction along said first linear guide (5, 28), ahand drive, said hand drive including a hand drive handle (14, 40, 47,54) moveable along a substantially linear path of motion substantiallyperpendicular to said guide direction of said first linear guide (5,28), said substantially linear path of motion of said hand drive handle(14, 40, 47, 54) having a fixed direction, a lever arm connecting saidhand drive and said sample carrier and deflecting a motion of said handdrive handle into a motion in said guide direction of said first linearguide, and a knife carrier in a front region of said microtome, saidknife carrier having a back face downwardly and forwardly inclined.